Dimming LEDs with Capacitors?

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ron3090

New Member

• Jul 20, 2010

• #1

Hello! I'm trying to make a circuit that gradually dims an LED by saturating a capacitor. Once the capacitor is full, I need to be able to discharge it and light the LED, then switch back over to charging it again. I've been racking my brain for weeks on this one, and I figured there must be a simple way to do such a thing. Any help?

 

audioguru

Well-Known Member

Most Helpful Member

• Jul 20, 2010

• #2

Bill Bowden's Fading RED eyes circuit uses a triangle generator that drives transistors that slowly fade and brighten LEDs.

 

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R

ron3090

New Member

• Jul 20, 2010

• #3

How about this I just came up with?
Will it do what I need?
All Diodes are LEDs and ignore the units.

 

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audioguru

Well-Known Member

Most Helpful Member

• Jul 20, 2010

• #4

Your circuit is missing a power supply.
It is also missing an oscillator to make the LEDs slowly dim and brighten.
Some of the transistors are backwards and upside down. The LEDs are also upside down.
One transistor is shorted.
All transistors are missing base current-limiting resistors.

A schematic is usually drawn with 0V at the bottom and the positive power supply source at the top.

 

Last edited: Jul 20, 2010

Dr_Doggy

Well-Known Member

• Jul 20, 2010

• #5

i think you want a circuit like this, the second one is with transistors, i may not have done proper resistor values, the blue and green wire are your switching, ones positive, one negative, also you may want to use FET's for your switching, but dont quote me on any of this!!!!

 

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ronv

Well-Known Member

Most Helpful Member

• Jul 20, 2010

• #6

simple flasher

Here is one that takes advantage of the avalanche of the transistor.

 

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C

circuitramon

New Member

• Aug 7, 2010

• #7

does any body have the circuit board diagram to make 5 or more leds to light in in a sequential mode for either 1, 2 or 3 times and then stay on until power is off.

 

Grossel

Well-Known Member

• Aug 8, 2010

• #8

circuitramon said:

does any body have the circuit board diagram to make 5 or more leds to light in in a sequential mode for either 1, 2 or 3 times and then stay on until power is off.

Click to expand...

You need one "ring counter" ande one regular counter (to count number of rounds). Basic digital corcuit